We investigate to what extent genuine social preferences can explain observed other-regarding behavior. In a social dilemma situation (a dictator game variant), people can choose whether to learn about the consequences of their choice for the receiver. We find that a majority of the people that show other-regarding behavior when the payoffs of the receiver are known chose to ignore them if possible. This behavior is inconsistent with genuine other-regarding preferences. Our model explains other-regarding behavior as avoiding cognitive dissonance: Peo- ple do not behave fairly because they genuinely care for others, but because they like to think of themselves as being fair. The model can explain our data as well as earlier experimental data.